Lift selector employing wiper arms serially engaging a bank of diode interconnected contacts



United States Patent 3,528,528 LIFT SELECTOR EMPLOYING WIPER ARMS SERIALLY ENGAGING A BANK OF DIODE INTERCONNECTED CONTACTS Nigel Victor Carruthers, Billingshurst, England, assignor, by mesne assignments, to US. Philips Corporation, New York, N.Y., a corporation of Delaware Filed Mar. 20, 1967, Ser. No. 624,532 Claims priority, application Great Britain, Mar. 28, 1966, 13,552/ 66 Int. Cl. B66b 1/06 US. Cl. 187-29 2 Claims ABSTRACT OF THE DISCLOSURE An elevator floor selector unit having wiper arms representing the movement of the elevator for the up and down direction respectively and a bank of contacts for each arm, each contact representing a floor. Each bank of contacts is interconnected by means of diodes, the diodes in the up bank being connected in a direction opposite to those in the down bank. The elevator selection is pulse operable, and a wiper arm may be provided on each bank to indicate the presence of further calls in the direction of travel.

This invention relates to a lift selector for a lift system serving several floors, comprising movable wiper arms and contact banks each associated with a wiper arm and each comprising a series of successive contacts of which a first contact is associated with the ground floor, a last contact is associated with the top floor and intermediate contacts are individually associated with intermediate floors, whereby the wiper arms are arranged to move over the series of contacts in correspondence with the movement of the lift car in the lift shaft.

The selector in a lift system is used to give information of the position of the lift car in the shaft and this information is used to control the lift movement and to illuminate position indicators.

It is the object of the invention to provide a selector of the type referred to which provides in a simple manner, directional signals upon application of call signals thereto. These directional signals are required to control the movement of the lift car in the lift shaft.

A lift selector according to the present invention is characterized in that in each of two contact banks each contact of the series is connected to the next successive contact of the series through a rectifier, the rectifiers being connected so as to provide a unidirectional signal path between the first and last contact of the series, the signalling paths thus provided in the two contact banks being conductive in opposite directions, whereby call signals for each particular fioor in the form of a fixed polarity voltage are arranged to be applied to the contacts in the two contact banks corresponding to said floor, said call signals being passed in different directions through the two signalling paths and when passing through the wiper arms providing directional signals for the control of the lift movement.

In order that the invention may be readily understood two examples of a selector in accordance therewith will now be described with reference to the accompanying drawings, in which FIG. 1 shows a first embodiment, and

FIG. 2 shows a second embodiment as a modification of FIG. 1.

In FIG. 1 of the drawing a uniselector is shown for a six floor lift system. The selector comprises two banks of contacts A, B for the down up directional signals respectively. Each bank has six contact members 10,

p CC

11, 12 13, 14, 15 and 20, 21, 22, 23, 24, 25 respectively, which are associated with the respective floors. The contacts 10 and 20 being associated with the ground floor, the contacts 11 and 21 being associated with the first floor, etc. The selector has the Wiper arms 17 and 27 in respect of each bank of contacts and the arms are ganged together to move in unison and are operated by pulses generated by the car movement. When the lift car is in the zone of the ground floor the contacts 10 and 20 are engaged by the arms 17 and 27 respectively, when the lift moves out of the zone of the ground floor into the zone of the first floor the arms 17 and 27 engage the contacts 11 and 21 respectively and so on. The wiper arms are connected to the lines 18 and 28 respectively over which signals may pass to a control device. A signal to call the lift down passes over line 18 of bank A and a signal to call the lift up passes over line 28 of bank B to the control device of the lift system, which controls the lift movement.

Between each two adjacent contacts in the banks A, B, diodes are connected which act as one-way blocking or steering devices for electric signals. The diodes in the bank A being connected to be conductive in the direction from contact 15 to contact 10 and the diodes in bank B being connected to be conductive in the opposite direction from contact 20 to contact 25.

In operation if a case is considered of the lift car at the fifth floor then the wiper arms 17 and 27 will be contacting contacts 15 and 25 in banks A and B respectively. When an intending passenger at the third floor presses a button on the third floor landing a call signal in the form of a negative voltage is applied to contacts 13 and 23 of banks A and B. Because of the direction of conduction of the diodes the call signal can only be passed from contact 23 through to contact 22, 21 and 20 of bank B and is prevented by the blocking action of the diode between contacts 23 and 24 from passing to the wiper arm 27 and hence to line 28 of bank B to initiate an up-directional signal. The reverse is the case, however, with bank A since the call signal applied to contact 13 of this bank is blocked from passing to contact 12 and is steered to pass in the direction of contacts 14 and 15 and hence via arm 17 onto line 18 of bank A to give the required down-directional signal to the control device. When the car has replied to the call from the third landing and arrived there, the wiper arms 17 and 27 will be engaged with contacts 13 and 23 respectively. If the passenger now enters the car and pushes the ground floor button a negative voltage is applied to the contacts 10 and 20 of the selector. Again due to the blocking action of the diodes in the bank B the call signal will not be transmitted onto lines 28 of this bank, but it will be transmitted onto line 18 of the bank A to give the required down-directional signal to the control device.

In the second example shown in FIG. 2 the same basic arrangement of FIG. 1 is retained but this is modified by the addition of a further wiper arm 17 on bank A which is mechanically ganged to the arm 17 and is connected to a line 18'. The mechanical gauging is such that the arm 17 rests on the contact member immediately adjacent that on which the wiper arm 17 rests. An additional contact 16 is provided next to contact 10 for engagement by the arm 17' when the lift is at the ground fioor. In bank B a further wiper arm 27' is provided similarly ganged to the arm 27 of this bank and connected to a line 28. An additional contact 26 is provided for when the lift is at the top floor and the selector is in the position as illustrated. In practice it is easier to provide two further banks of contacts each with its own wiper arm rather than to add an additional arm to existing banks. The additional banks would be wired in parallel with the existing banks. It will be noted that in bank A and bank B the further arms 17, 27' are on opposite sides of the arm 17 and 27 respectively and in fact are directionally so placed so that for the bank A the further arm 17' reaches the contact member of a calling floor ahead of the wiper arm 17 when the lift car is travelling downwards, while for the bank B the arm 27' reaches the contact member of a calling floor ahead of the wiper 27 when the car is travelling upwards.

By adding this feature the control device of the lift system can determine in a particularly simple manner that a particular call at any floor is the last call in the direction that the car is travelling. The necessity to detect this condition stems from the operational requirement of the lift system that the direction of car travel will be maintained unless there are no further calls in the direction of car travel.

As an illustration of the operation of the embodiment of FIG. 2 let it be supposed the car is at floor 5 with no calls on the system, and then a call is placed at floor 3. The call signal injected on the contacts 13 and 23 passes through the diodes on bank A to contacts 14 and 15, and thus onto wipers 17 and 17'. When the car leaves floor 5 wiper 17 will move to contact 13 and wiper 17 to contact 14, thus both will retain the call signal. As the car enters floor 3 wiper 17' will move to contact 12, where it will receive no signal as the diode between contacts 12 and 13 is in the reverse direction. Thus the control device will sense that this is the furthest call in the downward direction.

A similar process occurs when the car is required to travel upwards to answer a call, with the wiper 27' of bank B one step in front of the wiper 27 in the upwards direction.

The diodes used are conventional solid state silicon or germanium type diodes.

What is claimed is:

1. Selector for a lift system serving several floors,

comprising a pair of movable wiper arms, a pair of contactbanks each associated with a wiper arm, each contact bank comprising a series of successive contacts, the first contact being associated with the ground floor, the last contact being associated with the top floor and intermediate contacts being individually associated with intermediate floors, said wiper arms ganged together and movable over the series of contacts in correspondence with the movement of the lift car in the lift shaft, each contact in each of said pair of contact banks connected to the next successive contact of the contact bank through a rectifier, the rectifiers being connected so as to provide a unidirectional signal path between the first and last contact in each of the series, thereby establishing a signal path in each of the two contact banks conductive in opposite directions, call signals for each particular floor being in the form of a fixed polarity voltage and arranged to be applied to respective ones of the contacts in the two contact banks corresponding to respective ones of the floors, said call signals being passed in different directions through the two signalling paths and when passing through the wiper arms providing directional signals for the control of the lift movement.

2. Selector as claimed in claim 1 wherein a further wiper arm is provided for each of the wiper arms moving in the said two contact banks, said further wiper arm being arranged in each contact bank to contact the same contacts as the wiper arm it is associated with, and a relative displacement of one contact distance in the direction of conductivity of the signalling path in said contact bank.

References Cited UNITED STATES PATENTS 2,827,981 3/1958 Eames et al. 18729 3,408,502 10/1968 Gardner l8729 BENJAMIN DOBECK, Primary Examiner 

